 import React, { Component } from 'react';
 class DemoState extends Component {
  constructor() {
    super();
    this.state={
      count:10
    }
  }
  render() { 
    return ( 
      <div className='demo-state'>
        <h3>01.定义状态</h3>
        count累加:{this.state.count}
      </div>
     );
  }
 }
  
 export default DemoState;